1. Field of the Invention
The present invention relates to an interface connector for protecting against electromagnetic interference, and more particularly, to an interface connector which ensures a tight connection, a stable signal transmission and an effective prevention from electromagnetic interference of external and self-producing magnetic waves.
2. Description of the Prior Art
In all kinds of electric circuit, the circuit board sometimes has to be divided into many sections due to space restriction or other conditions. Signal cables are utilized to connect signals. Especially, flat interface connectors with advantages of saving space and facilitating assembly are widely used in microelectronic devices. However, the problem with electromagnetic interference between the external and self-producing magnetic waves has to be overcome. In addition, all wires of the interface connector are kept away from one another at regular intervals such that the transmission impedance of the interface connector is consistent.
A conventional protection of the interface connector against electromagnetic interference includes a metal protection layer (e.g. conducting adhesive tape) stuck to the surface of the interface connector by means of back glue (e.g. double-sided tape). This metal protection layer serves to protect against the electromagnetic interference. In consideration of cost and other factors, the double-sided tape is often used. However, its adhesion can""t meet the requirement to stick the conducting adhesive tape. Moreover, it""s not heat-resistant. This kind of glued joint easily fails after use for a longer period. Furthermore, the metal protection layer is sputter-coated to the conducting adhesive tape made of nonwoven material. The nonwoven surface of the conducting adhesive tape has pores so that the protection effect against the electromagnetic interference is very poor. Moreover, the softness of the conducting adhesive tape after sputter coating treatment is also poor so that the flexibility of the interface connector is affected.
Taiwanese Model Utility No. 415692 discloses an interface connector against electromagnetic interference (see FIG. 1). The interface connector includes a metal protection layer 20 formed on the surface of both ends thereof through sputter coating with materials of aluminum and copper. The metal protection layer 20 can also be formed on the PET-film through vapor deposition or sputter coating. Hot melt adhesives 30 are interposed between the metal protection layer 20 and the interface connector 10. Therefore, the metal protection layer 20 is used to protect against the electromagnetic interference. However, this structure has following drawbacks:
1. The hot melt adhesives 30 are easily melted by heating while cracked after being dried. Thus, they are often softened at high temperature or even seep out after being melted. They can also be hardened and cracked after use under high temperature condition so that their sealing effect is lost. Accordingly, the self-producing magnetic waves are discharged, thereby leading to electromagnetic interference with the external electromagnetic waves.
2. The metal protection layer 20 formed through sputter coating or vapor deposition requires coating cost and work hours, thereby leading to a negative effect on cost reduction and competitiveness promotion. Moreover, the flexibility of the interface connector 10 is also affected due to the formation of the metal protection layer 20.
3. The thickness of wrapping layer of PET-film formed by vapor deposition or sputter coating and of the conducting adhesive tape is uneven, thereby leading to uneven impedance and affecting the protection effect against electromagnetic interference.
4. The hot melt adhesives 30 are non-transparent so that the interface connector 10 is easily squeezed during the processing so that it""s uneasy to find when the pitch of all signal lines is changed. Accordingly, it affects the smoothness of signal transmission impedance.
It is a primary object of the present invention to eliminate the aforementioned drawbacks and to provide an interface connector to protect against electromagnetic interference which includes a layer of insulating coating of mylar or other heat-resisting polyester. In addition, the layer of insulating coating has metal sputter coating against magnetic discharge to effectively protect against electromagnetic interference between the external and the self-producing electromagnetic waves. Furthermore, it""s not required to wrap the conducting adhesive tape so that the processing procedure can be simplified and the production cost can be reduced.
It is another object of the present invention to provide an interface connector against electromagnetic interference which is required to be cleaned before sputter coating since the mylar material has smooth surface and is pore-free. After sputter coating treatment, the thickness of the metal coating layer is uniform and even smaller than that of the conducting adhesive tape of the prior art. Accordingly, the transmission impedance is consistent, thereby increasing the protection effect against electromagnetic interference.